Brake



Jan. 6, W E WHITE 2,867,297

BRAKE Filed Dec. 28. 1953 5 Sheets-Sheet 1 NVE/V702 WML/AM E. WHITE BY- ATTORNEY Jan. 6, 1959 w. E. WHITE BRAKE 5 Sheets-Sheet 2 Filed DeC. 28. 1953 @H Uimw...

INVENTOR. WML/AM E. WH/TE BYM 9 m A T TOIENE Y Jan. 6, 1959 w. E. WHITE 2,867,297

BRAKE I Filed Dec. 28. 1953 5 Sheets-Sheet 3 'i' ger-.Yami d Ef; E

JNVENToR. WILL/AM E. WH/TE BVM 5M l ATTORNEY Jan. 6,. 1959 w. E. WHITE 2,867,291

BRAKE I Filed Deo. 28. 1953 5 Sheets-Sheetg 7a\ T T i Z-gi' 4 JNVENToR. WML/AME. W/f/TE WMS@ A T Tom/EY Jan. 6, 1959 W, E, WHWE 2,867,297

BRAKE Filed Dec. 28. 1953 5 vshams-sheet 5 1N VEN TOR.

f1 7" TOENE Y actuated brakes for heavy duty applications.

United States Patent BRAKE Application December 28, 1953, Serial No. 400,428 12 Claims. (Cl. 188 78) yThis invention relates to brakes and more particularly to an internally expanding shoe brake wherein each of the shoes is individually self-energized in either direction of vehicle motion. This brake is especially adaptable for use in high kinetic energy absorbing applications, such as trailer braking.

The braking art has extensively utilized pneumatically While pneumatically controlled brakes have been satisfactory in some respect, they are seriously deficient in the matter of pedal travel required for actuation and controllability of braking effectiveness. The present invention proposes to eliminate such devices as pneumatically actuated linkages Which'are used to mechanically apply the brake, and substitute therefor a hydraulic system for applying the friction elements of the brakemechanism. Ruggedness and reliability in operation are prime requisites in the heavy duty brake constituting the present invention.

It is therefore an object of the invention to provide a hydraulic brake for heavy duty applications which combines the featuresof eifectiveness,reliable performance and low cost.

Another object of the invention is to realize increased braking effectiveness in one direction of Vehicle motion;

vAnother object'of the inventionis to obtain an adjustable brake of increased strengthwhich is adapted to be self-energizing with respect to the brake drum. i

Another object f the invention is to provide improved anchorage for thel brake by novel location of the torquetaking member withinthe wheel cylinder.

'A still further object of the invention is to provide improved means for laterally positioning the shoes in operative position.

'The above and other objects and features of the invention will appear-,more fully hereinafter from a consideration of the following description, taken in connection with the accompanying draWings,-wherein aplurality of embodiments of the invention are illustrated by way of example. In the drawings: j Figure l is a side elevation of the brake assembly illustrating in partial section the wheel cylinder, adjustor, applying lever, and a portion of the torque spider;

Figure 2 is a section view taken through one of the wheel cylinders on line 2 2 of Figure 1;

Figure 3 is a section view taken on the line 3 3 of Figure l;

Figure 4 is a section View taken along the axis of the Wheel cylinder and through the shoe applying mechanism on the line 4 4 of Figure l;

Figures 7, 8, and 9 aresec'ton views taken respectively on the lines 7 7, 8 8, and 9 9 of Figure 6.

Referring tothe embodiment disclosed in' Figures l v to 5, a pair of brake shoes 10 and 12, each having Ya friction material lined rim`14 and transverse strengthening webs 16 and 18, are-hydraulically actuated by a pair of wheel cylinders 20 and 22 into engagement with a rotatable drum 24 mounted on anti-friction bearings positioned on a fixed member such as the axle 26.l

A torque spider 28 is suitably secured by a plurality of fastening members 30 to a fixed member, such as axle housing iiange 32, and is provided with radiallyl extending projections 34 and 36 which are oiiset to extend on either side of the Wheel cylinders 20 and 22 thereby securing them in operative position. l

An anchor pin 38 is received through the mid portion of each of the Wheel cylinders 20 and 22 and is secured on either side to the projections 34 and 36 of the support plate 28. v v

Reciprocably mounted in each of the wheel cylinders 20 and 22 are a pair of oppositely acting pistons 42 having centrally located recesses 44 on adjacent ends thereof bearing against anchor members 38. Operatively associated with each of the pairs of pistons 42 are thrust links 46 and 48.v The thrust link 48 is threadedly received in an adjusting mechanism .designated generally by reference numeral'S. An'applying lever 52 associated with one end of each of the shoes is pivoted at 54 and actuated by thrust link 46 at opposite end 56. Shoe ends 5S, appliedby levers 52, abut the latter-intermediate the applied and pivoted ends thereof to multiply the actuatingforce exerted by thewheelcylinder on the end of the'shoe associated therewith.' /Woodrutf keys L60 areinterposed between thelevers 52 and the endsy 58 of the shoes to permit pivotal and slidingmovement of` -the webs .1'6 and 18 of the respective shoes thereby preventing the V.anchor block 66 from turning with the threaded link 48 when the latter is caused to rotate crown wheel74 meshing with star Wheel 7 6. v v The shoes 10 and 12 are free to pivot about end 62 by reason of the convex shape of post 68 and the mating recessed portion in the webs 16 and 18 of the shoes.

To laterally position the shoes 10 and 12, I provide shoe guiding -means consisting of bands 77 which are secured to the torque spider 28 at points 79. The bands 77 are received between the webs 16 and v18 of the respectiveshoes and-abut on either side4 with the inner portion of the webs of shoesl() and 12. This abutting relation l of the bands 77 `with the webs 16 and 18 of the respec- Figure 5 illustrates in perspectivethe adjust'oradapted tive shoes prevents movement of the shoes in either lateral direction and also prevents lateral turning of the shoes about ends 58 and 62.

Each of the anchor members 38 constitutespart o f the hydraulicA system." The anchors 38 are provided with -centrally located, longitudinally extending passages 78 communicating with chambers 84 wheel cylinders 20 and 22. External conduit 86 communicates the chambers 84 in Wheel cylinders 20 and 22.

'A pair of'return springs 87 and 88 interconnect the two shoes 10 and 12on either side of the torque spider 28 to yieldably retain the shoe ends 58 and 62 in retracted position.

Referring now to the.embodimentfdisclosed in` Figures 6 to 9, parts corresponding to those previouslymen- 2,867,297 Patented Jan. 6, 1959 tional will be. fefeied. t* brittle, reference. numeral..

with the subscript a affixed thereto.

' j and 22a into Africtionalb engagement.withL `a rptatahledrum (not 'ShQWi1 A. taurus Spider 2.8.. is suitably Secured by. fastening. 'members 3.041. t0.. e. neurotetablem @e Such es an axle Hana@- Tghe torque Spider-2.8.4.@ prendas! with axially olset projections34a` and 36g/ extending Vori either side of wheel cylinders 2tlg, and 22a.

Anchors 38a. are tranls/versely4 receiyed throngh openings provided iii themidapertien, of the wheel. cylinders 2041 and 22a The auhorsa are gestione@ at; opposite ends. in theaxiallyoftset projections34erand36a.` Reciprocably receivedV in each org-the wheel lcylinders Zilla and 2.2mm apair. 0f oppesiteiy actingpisteus 42a.. the adje: cent ends of which are recessedat 4 4zijand abut with the, anchor 33g. EachY of thevshoes is adaptedffor pivotal and Sliding movement. about either of their. opposite ends 155e and. 6.2;@1 thus permitting the shoe. to maintain concentricity with the rotatable drum 24a. and. further permitting pivotal.- actuation of the shoe about. either of the opposite endsA thereof. y i

One uend 5.8.41 of. each of the `shoes 10a and- .12.a is prof vided withra lever 52a. atSfla .andactuatedby input` force supplied bythe. piston at 56a. A key. tlahavng pinned Connection. 90. with lever 52a. abutswith. a block insert 92which ispositionedbetween thewebs. 16a. and 18a at the end` 58a, of. each, of the vshoes. 10aA andlZa. This. arrangement of parts permits eachof the shoes 10a; and.112a to pivot. about pinnedconnection 9.0.and further. allows the shoetoshiftby sliding.actionbetweenthe block-.in-- sert92 andkey 60a.'

A i polygonal adjustor. 50a mounted on a. stemA 94 which is.- journaled at .points 96 Ain webs.. 16,:` and* 13a.A is, inabuttingrelation with aside 98-of .theblockinsert 92V.. This abuttingrelationf ofithe. polygonal-v adjustor.- with i therside 98 of the block insert 92 denes thel'extentv ofiretraction of the shoe end .58d associated therewith.'

`Each shoe is positioned laterally by a'band 77a suit-V ably securedto. the torque yspider 28a at points 79a. The. ends of the `bandi77gzfpro'ject within the space between the strengthening rims 16a and'lSa of brake shoes 10a and 12a. The 'widthof the band17-7a is approximately equal to the distance betweenthe two websloa and 18a, and

the baudVv 77a accomplishes lateral positioning of the` shoes by abuttingcontact with opposite Vinner surfaces Inserted between the endf 62o of the shoes 10a and 12a :and the'piston 42u' isfa key llll having a slightly convex 'face contacting ahardened.` insert 102 which is received inthe outer end ot the pistonfZa.y The purpose of the slightly convexfshape of the one' endY ofikey 10i) isA to permit pivotaimoverire'nt'of; the sh'oexabout end 62a.

The 'operation of the embodiment; vslvi'ovvn in 'Figuresl tois as follows; 'A 4' u i A Hydraulic'pressure fromV aV master cylinder source (not shown) is transmitted .through'passage .7 84fin, anchor`38 to chamber S4fin'vvheel cylinder 20 As ythe'pis't hs 42 are s'preadapart'fundarV the actionoff the' ilidpressure transmitted the1"eto,'"the` two wheelcylindersfjandfZZ are intercommunicated ,byway ofrfexternali'conduit- 'S6-.seti fecting simultaneously the sameV operation When the pistons'42 in each of thecylinders 2Q and' V22,;are'sphread apart, a greater applying effort isfexertedj on end S of each of the shoes and 12 because ofthernultipllif` lever 52'. This means that with ya giveninputtorce i'n the n wheel cylinder,` the shoe end vSwftvill beuappliedymlore readily against the rotatingdum24, I i A Assuming a direction Volfdrurn rotation. in the direc:v tion indicated in Figure 1,"the two shoesywillanchorat their respective A.ends 6Y2-`onuadjustp-rsv 565i the anchoring MadiS'Jheu; transmitted" thloush. pistage )4Z-to the au; chors 38; It will be noted" that anchoring load is iransbodiment, differences in operation of the two devices-are v y related tothe adjustment feature .andin the manner in nritted t9, aiihors. 3 8 independently, ot wheel. cylinders. 2.0 and 22. The only torque reaction which is exerted on wheel cylinders 20 and 22 is that causing a slight turning of the Wheel cylinder about anchor 38 due to the slight angle of contact between the threaded thrust link 48 and the piston associated therewith, The tendency of the wheel cylinder to twist under the action of a part of the anchoring load is compensated for by cont-act of the flat sides ofA the wheel cylinder with` the torque spider 285, Substantially all of the anchoringwlloadw is. transferredl di rectly to the anchor independently oi. the wheely cylinders 20 and 22. Y i

when the-..b.raking.- efort exerted; by: the operator is released the twopairs of returnvsprings87 and 88 associated with the ends 58 andl 62 of the shoes 10 and l2 n return them to. retracted position.

Assuming now opposite direction of drum rotation, ycnqe-ratn' generatedl preSSLlre will `Spread the pairsof pistons,V in each of theA wheel` cylinders 20y and22- apart, applying first shoe en clziiS-and.` thenshoe. end. 62;. Shoe end; 5S, is returned to retracted position. and the shoe, anchors-j thereagainst. The, anchoringloadl is transmitted through lever 52 to the anchor 38 via the piston 42.associated therewith. TheV anchoringload, is transmitted. to

the. anchor 3 8 findependentlyl of the wheel cylinders 20 vand 2,2, excepting a` slight tendency to turn the wheel" cylinderv about. the. anchor which is; compensated for'by the. lflatv characteristic.- of the side. of. the wheel cylinder contacting the. torque spider 28. When the input force on. theipi'stonsA isgreleasedy the.- pair of return springs 37' and '8.8i returnthe. shoe ends 62 toretracted position.

Whenthe lining on theshoes hasworn. sufciently to necessitate anadjustment, the stem. 75 `is rotated by a suitabletool inserted. through an opening in the brake assembly. which causesl turning oflzstar Wheel 761 meshing with crown wheel 74. Turning of stem ultimately produces.v rotation of thethreaded, thrust link;.48 inthe threaded' opening 6.4;ofvi-thetadjnstor; block 661m, that the adjustoriblock-. is.causedto lmove away `from thewheel cylinder spreading the end of the shoe 62 and varying thevretracted position thereof.- When theend of the shoe 62 is adjusted outwardly, concentricity. of thel shoe. '.with

thejdrum isre-established by slidingof theshoe on ends-58 and 62 causing the shoe to shift along4 aline connecting the opposite ends thereof.

'It willbe noted that asv the `torque reaction from brak.- `ing is transmitted to the ancho`ri38 the anchoring'load is communicated to projections 34 and 36 equidistant from the center portion ofthe torque spider 3:2.y This is what is` known as centermountprinciple, the. pur- `pose of this construction is to eliminate any lever arm through which the anchoringload' can be multiplied in being transmitted to afixed members so that thefbrake construction can absorb greater-torqueload's fora given size of the components.

The. operation of the brake-illustrated in'Figures'f-to 9 is substantially the same as that in they previous emwhich braking torque is .transmittedqthrough the pistons 42a vto the.anchor38a.;

Assuming rotationvin the.direction-indicated irl-Figure 6 the two shoes .anchor at shoe end 62a. The web s16a and'18a contacting the key1p00 itransmit ther'torque. re-

action to the anchor 38a via the piston associated therewith-.l/The contacting .pointbetween `the key and the'plugv102 permits pivotal movement of the shoe as j end 58a is outwardly applied against the drurn. The i shoe, end 58a is applied by lever 52a actingthroughthe key 60a abutting with block9r2r.

The shoe is adjusted by rotatingy the stemk 94 which turns the'polygonal adjustor 50a bringing au adjacent side into abutting ,contact lwithr the bl'ockg92.Y Thelpolyg'- onal" adjustor isso` designedl that successive adjacent sides are farther removed from the center of rotationof the adjustor and, as the distance between the block v92 and the stern 94 is increased, the stem 94 abutting with the two webs 16a and 18a causes outward movement of shoe end 58a. When the shoe 58a is adjusted outwardly concentricity of the shoe and drum 24a is re-established by shifting movement of the shoe as it slides on ends 58a and 62a.

Although only two embodiments of the invention have been described it will be apparent to those skilled in the art that various changes in design and location of the parts may be made without departing from the scope of the invention.

I claim: i v d' l. A brake comprising a torque spider, a pair of in dividually self-energizing brake shoes each having arim and two transverse strengthening webs, la iluid motor mounted between each of the adjacent ends of said shoes and operatively connected therewith, axially offset projections of said torque spider extending on either side of said wheel cylinders, an anchor pin laterally received through the midportion of each of said wheel cylinders and positioned in said projections, shoe positioningmeans clamped to said torque spider and received between the transverse webs on said shoes, a pivoted applying lever associated with one end of each of said shoes, a thrust link operatively connected to the end of each of said levers, means for enabling the ends of said shoes associated with said levers to slide and pivot on said levers intermediate the ends thereof, an adjustor associated with one end of each of said shoes consisting of a post positioned in the webs of said shoes to permit pivotal movement of said shoes thereon, a boss located on the midportion of said post and positioned between the webs of said shoes to prevent turning of said` adjustors, and an externally threaded thrust ylink received in an opening inl each oflsaid adjustors, said thrust links bearing against pistons in said fluid motors and adapted` to vary the retracted position of the ends of the shoes associated therewith. .t

2. A brake comprising a torque spider, a pair of individually self-energizing brake shoes each having a rim and two transverse strengthening webs, a pair of Huid motors located between adjacent ends of said shoes, a laterally extending anchor pin transversely received through each of said Huid motors, axially offset projections integral with said torque-taking member and extending on either side of said Huid motors, said anchoring pins being received through said fluid motors and positioned at opposite ends thereof in said projections, a pivoted applying lever operatively interconnected between an opposite end of each of said shoes and said uid motor, the end of said shoe associated therewith being adapted for sliding and pivotal movement thereon, an adjustor associated with the other ends of said shoes, each of said adjustors having a portion received between the strengthening webs of the shoe and a post received in the webs of the shoe end to perimt pivotal movement of the shoe thereon, a threaded thrust link received in an opening in said adjustor and operatively connected to said shoes through said adjustor, meshing star wheels adapted to produce turning of .said threaded stem to vary the retracted position of the end of the shoe associated therewith, means received between the webs of said shoes and in abutment therewith for laterally positioning said shoes, and means for yieldably retaining said shoes in retracted position.

3. A brake comprising a torque taking spider, a pair of brake shoes each having a rim and two transverse strengthening webs, a huid motor with openings in thev shoes being Iadapted forr pivotal and sliding movement on said applying levers, axially spaced projections'on said torque spider extending on either side of said fluid motors to provide support therefor,l anchor members transversely received through the openings in said wheel cylinders,

said anchor members being mounted and taking support at each of the opposite ends thereof in said projections, each of said anchor members having longitudinal passages communicating hydraulic luid pressure to said duid motors, and a conduit interconnecting the passages in said anchors for imparting simultaneous applyingv eiort on the shoe ends associated with said fluid motors.

Y 4. For use in combination with a pair of arcuate brake shoes, a uid motor associated' with each of the adja` cent expansible ends of said shoes, a pair of oppositelyacting pistons reciprocably received in each of said fluid motors, a pair of thrustilinks positioned in the remote ends of each of said pair of pistons and operatively connected to adjacent shoe ends, an anchor member transversely received through aligned .apertures in said tluid motors and taking support at each end in torque-taking projections extending on each side of said fluid motors,`

pair` of adjacent expansible shoe ends, two oppositelyacting pistons reciprocably mountedin said uid motors, an anchorl member transversely received through openings in eachl of said fluid motors, eachof said anchor members beingsup-ported atu opposite ends thereof independently of the associated iiuid'motor, hydraulic passage means formed in .said lanchors to transmit fluid pressure to the associated fluid motor, the openings in saiduid motor which receive said anchors being sealed against iiuid'leakage' and 'thrust links operatively interconnecting said pistons and the expansible ends of said shoes, said pistons engaging said anchor to define the retracted position of said shoes and anchoring thereon as braking torque is transmitted thereto by the shoe ends bearing thereagainst, said uid motor being prevented from turning about said anchor by engagement of one side of the fluid motor with a fixed member.

6. A'fluid motor which is constructed and arranged to apply adjacent expansible ends of a pair of shoes associated therewith, said uid motor including a pair of oppositely-acting pistons reciprocably mountedtherein, and an anchor transversely received through openings which are constructed transversely in said wheel cylinder, said pistons abutting said anchor and transmitting torque thereto independently of said wheel cylinder as the shoe ends anchor through said pistons, said anchor being constructed as a part of the hydraulic system to introduce fluid pressure to said wheel cylinder via a longitudinally extending bore provided therein. u

7. In a brake, a brake shoe provided with a plurality of transverse strengthening webs, an actuatable thrust link operatively associated with an `actuating means, and an adjustor threadedly received on said link, said ad.- justor having a first portion which is received between the webs of said shoe and is proportioned to be locked therebetween to prevent relative turning of said tirst'portion with respect to the strengthening webs, and a second portion of said adjustor which is constructed integrally with said first portion and is received within notches of the brake shoe to enable pivoting movement thereon, said adjustor being in abutting relation with said shoe to impart a spreading force thereon as said thrust link is caused to turn in one direction.

8. In combination with a pair of brake shoes, a fluid motor associated with each of the adjacent expansible ends of said shoes, a pair of oppositely-acting pistons reciprocably received in each of said uid motors and an anchor extending, through aligned sealed; 'apertures constructed'in said Wheel cylinders', said anchors being supported at opposite ends thereof independently of 'said' huid-motors; the pairs of"l pistons bearing against said anchors lto define thel anchored and retractedv position of said-brake shoes;l

A9;; A fluid 'motor includingr a pair` of 'pistonszadapted toA apply` adjacentA expansibleV ends. of-a pair of brake shoes,-and an anchor transverselynextended through and substantiallyr'tilling aligned sealed openings in the midportion of said nid motor, ,said pistons engaging. said anchor and; transmitting torque, thereto,l said, anchor be,- ing provided with a longitudinaljpassage alording *hy-g draulic inlet` to and" exit from, said 'wheel cylinder, in actuatingsaid .pistons to applyzthe shoes associated therewith.'`

1i).` In aV brake, `av nonrotatable -me rnbter, an anchor member, arfluid motor including a' cylinder casing having,k

transverse openings in-the sides thereof, said anchormember being received lthrough :said lopenings in said,casing to become constructed and arranged' for mounting'saidl uid motor on saidj nonrotatable member, means for sealing said transverse openings' which receive said anchor members thereiny and a pair of vbrake shoes arranged to transm-it torque reaction' toVsaid vanchor member independentlyof the'cylindercasingof the luidmotor.

1'1` In a brake, a Huid motor anchoring means which are constructedseparately in saidmotorand are received through transverseopeningsl in-a part'of sairduid motonfor'mounting; it on aA fixed member, and a pair of brake shoes arrangedto transmit'thrust to said anchoring means independentlyof'V the cylinder;` ofisaid'fiuid motor..

l 12. Aheavy duty.hydraulicgbrale*comprising a fixed torque spider, a pair' 'ofA brake shoes having adjacent-exft pansible.v ends, each ofgsaid brake shoes havingan arcuate `frictioli-materialJlined` rim; and'a plurality ofspaced-v `apart strengthening t Webs, lateral Ipositioning meansY for' said'shoes' combinedl with saidtorque spider and-said" strengthening yvebs, hydraulicwheel cylinders carried by saidl torque spider andi-locatedlb'etween theadjacent'expansibleends1 of said shoes, ythrust links combined with said wheel cylinders atreach end thereof,y "oppositely lo#v cated applyinglevers each pivotally mounted at one end' on saidjtorquev spider' and 'swivablyconnected vto a thrust,

linkatfits other end, said"`l evers being arranged toptransmit applying thrustto thej ends of ,the shoes at a point lon the lever intermediate theV pivotal mounting portion `and operative connection with the thrust'link while providing for both pivotal and slidingmmovement of said shoes, means` arrangedy to receivev the anchoring. load 'of the shoes substantially independently-ofthe wheel cylinv ders,V each of said levers'servingntotransmit the anchor-- ing load of 'a lshoe tolsaidj'anchoringT means Yduring l braio" ing. in one direction,A andfadjnstor means combined with; one end ofreahofjsaidshnoesfor varying the retracted position thereof while maintaining a y substantially con;

stant piston displacement Vin. said Wheel cylinders.

References Citedinthe ileof thisv patent UNITED STATES PATENTS 

